# Class 9 Physics Chapter 8

Updated: 29 Oct 2023

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Class 9 Physics Chapter 8 is about “** Thermal Properties of Matter**“. This article includes topics such as Thermal Properties of Matter, Temperature, Heat, Measurement of Temperature, Thermometric Property, Temperature Scales, Centigrade or Celsius Scale, Fahrenheit Scale, Kelvin or Absolute Scale, Relationship between Different Scales of Temperature, Conversion between Centigrade and Fahrenheit Scale, Conversion between Centigrade and Kelvin Scale, Thermal Expansion, Thermal Expansion of Solids (

**), Thermal Expansion of Liquids, Real Expansion of Liquids, Apparent Expansion of Liquids, Coefficient of Real Expansion, Coefficient of Apparent Expansion, Anomalous Expansion of Water, Applications and Consequences of Thermal Expansion (Railway lines, Opening of Tight Jar Lid, Transmission Lines, Shrink-fitting of Axles into Gear Wheels, Expand Fitting Iron Ring to a Cart Wheel, Expansion Joints, Bimetallic Strip), Heat Capacity and Specific Heat Capacity, Heat Capacity (Thermal Capacity), Specific Heat Capacity (Specific Heat), Importance of High Specific Heat Capacity of Water (**

*Linear Thermal Expansion of Solids, Volume (Cubical) Thermal Expansion of Solids***), Latent Heat and Phase Change, Latent Heat of Fusion, Specific Latent Heat of Fusion, Latent Heat of Vaporization, Specific Latent Heat of Vaporization, Evaporation of Liquids (**

*Moderate Climate of Sea Shore, As a coolant**), Evaporation causes Cooling, Evaporation vs Boiling, Applications of Cooling by Evaporation (*

**Nature of Liquid, Temperature of Liquid, Temperature of surrounding, Presence of water vapor in Air, Area of the exposed surface of the liquid, Movement of Air, Dryness of Air, Air Pressure on the Surface of the Liquid****).**

*Cooling by Fans, Fever Control, Refrigerator*## Class 9 Physics Chapter 8 Notes

### Thermal Properties of Matter Notes

Class 9 Physics Chapter 8 Notes

Download Chapter 8 Notes### Class 9 Physics Chapter 8 SLO Notes

## Class 9 Physics Chapter 8 MCQs

### Thermal Properties of Matter

#### Introduction

1 The study of heat transformations into other forms of energy is,(a) Thermodynamics

(b) Kinematics

(c) Mechanic

(d) Dynamic

## Show Answer

**
Thermodynamics
**

2 When did the study of thermodynamics begin?

(a) 18th century

(b) 19th century

(c) 20th century

(d) 21st century

## Show Answer

**
18th century
**

3 What were the initial applications of steam engines during the Industrial Revolution?

(a) Powering smartphones

(b) Powering trains, factories, and water pumps

(c) Generating electricity

(d) Fueling automobiles

## Show Answer

**
Powering trains, factories, and water pumps
**

4 When were the concepts of thermodynamics linked to the motions of atoms and molecules?

(a) Around 1700

(b) Around 1800

(c) Around 1900

(d) Around 2000

## Show Answer

**
Around 1900
**

**To Download Complete Notes of Physics Notes 9 Class, Click on the given link.**

### Temperature

#### Internal Kinetic Energy

5 The measure of the degree of hotness or coldness of a body with respect to some standard is called,(a) Temperature

(b) Heat

(c) Energy

(d) Momentum

## Show Answer

**
Temperature
**

6 What is the average kinetic energy of molecules in a body related to?

(a) The color of the body

(b) The body’s weight

(c) The body’s volume

(d) The body’s temperature

## Show Answer

**
The body’s temperature
**

7 What is the symbol used to represent temperature?

(a) T

(b) C

(c) F

(d) K

## Show Answer

**
T
**

8 In which units is temperature commonly measured?

(a) A, B, C

(b) {}^oC, {}^oF, K

(c) X, Y, Z

(d) M, N, O

## Show Answer

**
{}^oC, {}^oF, K
**

9 What is the SI unit of temperature?

(a) Celsius ({}^oC)

(b) Kelvin (K)

(c) Fahrenheit ({}^oF)

(d) All of these

## Show Answer

**
Kelvin (K)
**

10 Which location is the hottest place on Earth?

(a) The Antarctic

(b) Death Valley, California

(c) The Sahara Desert

(d) The Amazon Rainforest

## Show Answer

**
Death Valley, California
**

11 What is internal energy in a substance primarily composed of?

(a) Potential energy

(b) Vibrational kinetic energy

(c) Rotational kinetic energy

(d) Both kinetic and potential energies

## Show Answer

**
Both kinetic and potential energies
**

12 In a solid, how do atoms primarily move?

(a) Randomly colliding with each other

(b) By stretching and contracting

(c) By jiggling in place

(d) By spinning rapidly

## Show Answer

**
By jiggling in place
**

13 Which type of kinetic energy is observed in a monoatomic gas at high temperatures?

(a) Translational kinetic energy

(b) Vibrational kinetic energy

(c) Rotational kinetic energy

(d) All of these

## Show Answer

**
Translational kinetic energy
**

14 In gases made up of molecules with more than one atom, what types of kinetic energy can these molecules possess?

(a) Only translational kinetic energy

(b) Translational and rotational kinetic energy

(c) Translational and vibrational kinetic energy

(d) Translational, rotational, and vibrational kinetic energy

## Show Answer

**
Translational, rotational, and vibrational kinetic energy
**

15 What happens to the temperature of a gas when energy is added to it?

(a) The temperature decreases

(b) The temperature remains constant

(c) The temperature increases

(d) The temperature fluctuates

## Show Answer

**
The temperature increases
**

16 What happens to the kinetic energy of molecules in a gas made up of more than one atom at high temperatures?

(a) It decreases

(b) It remains constant

(c) It increases

(d) It varies randomly

## Show Answer

**
It increases
**

17 In a liquid, where are molecules primarily confined to moving?

(a) In a straight line

(b) Randomly throughout the entire volume

(c) Within the confines of the liquid’s surface

(d) In a circular pattern

## Show Answer

**
Within the confines of the liquid’s surface
**

18 What type of energy is stored in liquid molecules as they approach each other due to attraction?

(a) Kinetic energy

(b) Potential energy

(c) Vibrational energy

(d) Rotational energy

## Show Answer

**
Potential energy
**

### Heat

19 The transfer of thermal energy from a hotter body to a colder body is called,(a) Heat

(b) Temperature

(c) Volume

(d) Energy

## Show Answer

**
Heat
**

20 What symbol is commonly used to represent heat?

(a) H

(b) E

(c) Q

(d) T

## Show Answer

**
Q
**

21 What SI unit is used to measure heat?

(a) Kelvin (K)

(b) Joule (J)

(c) Celsius ({}^oC)

(d) Watt (W)

## Show Answer

**
Joule (J)
**

22 When two objects with different temperatures are placed in thermal contact, what happens to their temperatures over time?

(a) Both temperatures remain the same

(b) The temperature of the hotter object decreases, while the temperature of the cooler object increases

(c) The temperature of both objects increases

(d) The temperature of both objects decreases

## Show Answer

**
The temperature of the hotter object decreases, while the temperature of the cooler object increases
**

23 The state when two objects have the same temperature is said to be:

(a) Thermal equilibrium

(b) Heat transfer

(c) Thermodynamic equilibrium

(d) Temperature balance

## Show Answer

**
Thermal equilibrium
**

24 When does thermal equilibrium occur between two objects initially at different temperatures?

(a) When they have equal masses

(b) When they are made of the same material

(c) After some time when they reach a common temperature

(d) When one object absorbs all the heat from the other

## Show Answer

**
After some time when they reach a common temperature
**

25 In thermal equilibrium, what can be said about the flow of heat between two objects?

(a) Heat flows from the hotter object to the cooler object

(b) Heat flows from the cooler object to the hotter object

(c) Heat stops flowing between the objects

(d) Heat flows randomly between the objects

## Show Answer

**
Heat stops flowing between the objects
**

### Measurement of Temperature

#### Thermometry

26 What is the range of temperatures that our hand can bear for sensing hotness or coldness?(a) A very large range of temperatures

(b) A very small range of temperatures

(c) The same range as a thermometer

(d) All of these

## Show Answer

**
A very small range of temperatures
**

27 What is the branch of physics that deals with the measurement of temperature?

(a) Thermodynamics

(b) Heat transfer

(c) Thermometry

(d) Kinetics

## Show Answer

**
Thermometry
**

28 What is an instrument called that is used to measure temperature accurately?

(a) Temperature gauge

(b) Heat sensor

(c) Thermometer

(d) Temperature meter

## Show Answer

**
Thermometer
**

#### Thermometric Property

29 What is the term for a property that increases or decreases uniformly with changes in temperature?(a) Variable property

(b) Temperature-independent property

(c) Thermometric property

(d) Invariant property

## Show Answer

**
Thermometric property
**

30 Which of the following is NOT an example of a thermometric property?

(a) Volume of a liquid

(b) Length of a solid

(c) Gas pressure

(d) Color of a substance

## Show Answer

**
Color of a substance
**

31 What is the most commonly used thermometric property?

(a) Electrical resistance

(b) Gas pressure

(c) Thermal expansion of materials

(d) Electromotive force

## Show Answer

**
Thermal expansion of materials
**

32 How does a liquid in a glass thermometer measure temperature?

(a) By changes in color of the liquid

(b) By changes in the state of the liquid

(c) By variations in the volume of the liquid

(d) By variations in the pressure of the liquid

## Show Answer

**
By variations in the volume of the liquid
**

33 Which liquids are commonly used in glass thermometers?

(a) Water and oil

(b) Mercury and alcohol

(c) Gasoline and acetone

(d) Sodium and potassium

## Show Answer

**
Mercury and alcohol
**

### Temperature Scales

34 What is a temperature scale or thermometric scale?(a) A scale used for measuring length

(b) A scale used for measuring time

(c) A scale used for measuring temperature

(d) A scale used for measuring weight

## Show Answer

**
A scale used for measuring temperature
**

35 What is another term for a temperature scale?

(a) Measurement scale

(b) Thermodynamic scale

(c) Thermometric scale

(d) Metric scale

## Show Answer

**
Thermometric scale
**

36 What are the two reference points on a temperature scale called?

(a) Fixed points

(b) Temperature points

(c) Arbitrary points

(d) Measuring points

## Show Answer

**
Fixed points
**

37 How many scales of temperature are commonly used?

(a) One

(b) Two

(c) Three

(d) Four

## Show Answer

**
Three
**

#### Centigrade or Celsius Scale

38 Who introduced the Celsius scale of temperature?(a) Daniel Gabriel Fahrenheit

(b) Anders Celsius

(c) William Thomson

(d) Lord Kelvin

## Show Answer

**
Anders Celsius
**

39 What is the other name of the Celsius scale?

(a) Centigrade scale

(b) Fahrenheit scale

(c) Kelvin scale

(d) None of these

## Show Answer

**
Centigrade scale
**

40 In the Celsius scale, what are the numerical values assigned to the ice point?

(a) 0{}^o C

(b) 32 {}^oC

(c) -273 {}^oC

(d) 100 {}^oC

## Show Answer

**
0 {}^oC
**

41 In the Celsius scale, what are the numerical values assigned to the stream point?

(a) 0 {}^oC

(b) 32 {}^oC

(c) -273 {}^oC

(d) 100 {}^oC

## Show Answer

**
100 {}^oC
**

42 What is the interval between the fixed points on the Celsius scale divided into?

(a) 360 equal divisions

(b) 100 equal divisions

(c) 180 equal divisions

(d) 212 equal divisions

## Show Answer

**
100 equal divisions
**

43 Each division of the Celsius scale is called:

(a) A degree Fahrenheit

(b) A degree centigrade

(c) A Kelvin

(d) All of these

## Show Answer

**
A degree centigrade
**

44 Each division on the Celsius scale is denoted by:

(a) {}^oC

(b) {}^oF

(c) K

(d) {}^oR

## Show Answer

**
{}^oC
**

#### Fahrenheit Scale

45 Who introduced the Fahrenheit scale of temperature?(a) Anders Celsius

(b) Daniel Gabriel Fahrenheit

(c) William Thomson

(d) Lord Kelvin

## Show Answer

**
Daniel Gabriel Fahrenheit
**

46 What is the numerical value assigned to the ice point on the Fahrenheit scale?

(a) 0 {}^oF

(b) 32 {}^oF

(c) -273 {}^oF

(d) 100 {}^oF

## Show Answer

**
32 {}^oF
**

47 What is the numerical value assigned to the steam point on the Fahrenheit scale?

(a) 0 {}^oF

(b) 32 {}^oF

(c) -273 {}^oF

(d) 212 {}^oF

## Show Answer

**
212 {}^oF
**

48 What is the interval between the fixed points on the Fahrenheit scale divided into?

(a) 360 equal divisions

(b) 100 equal divisions

(c) 180 equal divisions

(d) 212 equal divisions

## Show Answer

**
180 equal divisions
**

49 Each division of the Fahrenheit scale is called:

(a) A degree Fahrenheit

(b) A degree centigrade

(c) A Kelvin

(d) None of these

## Show Answer

**
A degree Fahrenheit
**

50 Each division on the Fahrenheit scale is denoted by:

(a) {}^oC

(b) {}^oF

(c) K

(d) {}^oR

## Show Answer

**
{}^°F
**

#### Kelvin or Absolute Scale

51 Who devised the Kelvin (Absolute) scale of temperature?(a) Daniel Gabriel Fahrenheit

(b) Anders Celsius

(c) William Thomson (Lord Kelvin)

(d) Sir Isaac Newton

## Show Answer

**
William Thomson (Lord Kelvin)
**

52 What is the other name of the Kelvin scale?

(a) Centigrade scale

(b) Fahrenheit scale

(c) Absolute scale

(d) None of these

## Show Answer

**
Absolute scale
**

53 What is the numerical value assigned to the ice point on the Kelvin scale?

(a) 0 K

(b) 32 K

(c) 273 K

(d) 100 K

## Show Answer

**
273 K
**

54 What is the numerical value assigned to the steam point on the Kelvin scale?

(a) 0 K

(b) 32 K

(c) -273 K

(d) 373 K

## Show Answer

**
373 K
**

55 What is the interval between the fixed points on the Kelvin scale divided into?

(a) 360 equal divisions

(b) 100 equal divisions

(c) 180 equal divisions

(d) 212 equal divisions

## Show Answer

**
100 equal divisions
**

56 Each division of the Kelvin scale is called:

(a) A degree Fahrenheit

(b) A degree centigrade

(c) A Kelvin

(d) All of these

## Show Answer

**
A Kelvin
**

57 Each division on the Kelvin scale is denoted by:

(a) {}^oC

(b) {}^oF

(c) K

(d) {}^oR

## Show Answer

**
K
**

58 What is the term for the lowest temperature at which the molecular movements of matter cease?

(a) Absolute heat point

(b) Critical temperature

(c) Absolute zero

(d) Molecular freezing point

## Show Answer

**
Absolute zero
**

59 What is another term for absolute zero?

(a) Molecular standstill point

(b) Zero temperature

(c) Kelvin Zero

(d) Molecular freezing point

## Show Answer

**
Kelvin Zero
**

60 What is the lowest temperature at which the molecular movements of matter cease?

(a) 0 \ {}^oC

(b) 32 \ {}^0F

(c) -273 \ {}^oC

(d) 100 \ {}^oF

## Show Answer

**
-273°C
**

61 Which scale is adopted in the international system of units?

(a) Celsius (Centigrade) scale

(b) Fahrenheit scale

(c) Kelvin (Absolute) scale

(d) None of these

## Show Answer

**
Kelvin (Absolute) scale
**

### Relationship between Different Scales of Temperature.

62 What is the formula to convert Celsius ({}^oC) to Fahrenheit ({}^oF)?(a) T({}^oF) = T({}^oC) + 32

(b) T({}^oF) = T({}^oC) \times \frac{9}{5} + 32

(c) T(°F) = (T({}^oC) + 32) \times \frac{9}{5}

(d) T(°F) = (T({}^oC) - 32) \times \frac{9}{5}

## Show Answer

**
T({}^oF) = T({}^oC) \times \frac{9}{5} + 32
**

63 Using the general conversion formula, what is the Fahrenheit temperature equivalent of 100{}^oC ?

(a) 3 2 \ {}^oF

(b) 212 \ {}^oF

(c) 100 \ {}^oF

(d) 273 \ {}^oF

## Show Answer

**
212 \ {}^oF
**

64 How do you convert Celsius (°C) to Kelvin (K) ?

(a) T(K) = T({}^oC) + 273

(b) T(K) = T({}^oC) \times \frac{9}{5} + 32

(c) T(K) = T({}^oC) – 32

(d) T(K) = T({}^oC) \times \frac{5}{9}

## Show Answer

**
T(K) = T({}^oC) + 273
**

65 What is the Kelvin equivalent of 37 \ {}^oC ?

(a) 37 K

(b) 273 K

(c) 310 K

(d) 100 K

## Show Answer

**
310 K
**

66 What is the formula to convert Fahrenheit ({}^oF) to Celsius ({}^oC) ?

(a) T({}^oC) = (T({}^oF) - 32) \times \frac{5}{9}

(b) T({}^oC) = T({}^oF) + 32

(c) T({}^oC) = T({}^oF) \times \frac{9}{5}

(d) T({}^oC) = T({}^oF) + 273

## Show Answer

**
T(°C) = (T(°F) – 32) \times \frac{5}{9}
**

67 What is the equivalent temperature in Celsius when a thermometer reads 32 \ {}^oF ?

(a) 0 \ {}^oC

(b) 32 \ {}^oC

(c) 64 \ {}^oC

(d) -32 \ {}^oC

## Show Answer

**
0 \ {}^oC
**

68 To convert Fahrenheit ({}^oF) to Kelvin (K) , you should use the formula:

(a) T(K) = (T({}^oF) - 32) \times \frac{5}{9} + 273

(b) T(K) = T({}^oF) + 32

(c) T(K) = (T({}^oF) \times \frac{5}{9}) – 273

(d) T(K) = T({}^oF) \times \frac{5}{9}

## Show Answer

**
T(K) = (T({}^oF) - 32) \times \frac{5}{9} + 273
**

69 What is the equivalent temperature in Kelvin (K) when a thermometer reads 98.6 \ {}^oF ?

(a) 310.15 K

(b) 273.15 K

(c) 370.15 K

(d) 546.27 K

## Show Answer

**
310.15 K
**

70 How do you convert Kelvin (K) to Celsius ({}^oC) ?

(a) T({}^oC) = T(K) – 273

(b) T({}^oC) = T(K) \times \frac{9}{5} + 32

(c) T({}^oC) = T(K) + 273

(d) T({}^oC) = T(K) \times \frac{5}{9}

## Show Answer

**
T({}^oC) = T(K) – 273
**

71 If the temperature on the Kelvin scale is 310.15 \ K , what is the corresponding temperature in Celsius ({}^oC) ?

(a) 100 \ {}^oC

(b) 273.15 \ {}^oC

(c) 37 \ {}^oC

(d) 310.15 \ {}^oC

## Show Answer

**
37 \ {}^oC
**

72 What is the formula to convert Kelvin (K) to Fahrenheit ({}^oF) ?

(a) T({}^oF) = T(K) – 32

(b) T({}^oF) = (T(K) - 273) \times \frac{9}{5} + 32

(c) T({}^oF) = T(K) \times \frac{5}{9}

(d) T({}^oF) = T(K) \times \frac{9}{5}

## Show Answer

**
T({}^oF) = (T(K) - 273) \times \frac{9}{5} + 32
**

73 If the temperature on the Kelvin scale is 310.15 \ K , what is the corresponding temperature in Fahrenheit?

(a) 40.33 \ {}^oF

(b) 98.6 \ {}^oF

(c) 570.27 \ {}^oF

(d) 680.33 \ {}^oF

## Show Answer

**
98.6 \ {}^oF
**

74 What is the freezing point of water in Kelvin (K) ?

(a) 0 K

(b) 32 K

(c) 273 K

(d) 100 K

## Show Answer

**
273 K
**

75 What is the normal body temperature in degrees Celsius?

(a) 32 \ {}^oC

(b) 36 \ {}^oC

(c) 37 \ {}^oC

(d) 40 \ {}^oC

## Show Answer

**
37 \ {}^oC
**

### Thermal Expansion

6 What is the term used to describe the increase in size of a substance on heating?(a) Contraction

(b) Dilution

(c) Expansion

(d) Compression

## Show Answer

**
Expansion
**

### Thermal Expansion of Solids

77 What are the three types of expansion a solid can undergo?(a) Linear, circular, and volumetric

(b) Expansion in length, width and depth

(c) Expansion in length, area and volume

(d) None of these

## Show Answer

**
Expansion in length, area and volume
**

78 When a solid is heated, why does it expand?

(a) The molecules move closer together

(b) The molecules vibrate through smaller distances

(c) The molecules vibrate through larger distances

(d) The molecules stop vibrating

## Show Answer

**
The molecules vibrate through larger distances
**

#### Linear Thermal Expansion of Solids

79 What is the term used to describe the expansion in length of a substance due to a change in temperature?(a) Superficial expansion

(b) Cubical expansion

(c) Volumetric expansion

(d) Linear expansion

## Show Answer

**
Linear expansion
**

80 The value of the coefficient of linear thermal expansion depends on:

(a) The temperature change

(b) The length of the substance

(c) The type of material

(d) The pressure applied

## Show Answer

**
The type of material
**

81 What is the symbol used to represent the coefficient of linear thermal expansion?

(a) \alpha

(b) \beta

(c) \gamma

(d) \delta

## Show Answer

**
\alpha
**

82 What is the unit of linear thermal expansion?

(a) Meters per second (m/s)

(b) Inverse degrees Celsius or inverse Kelvin (1/{}^oC \ or \ 1/K)

(c) Newton per square meter (N/m^2)

(d) Joules per kilogram (J/kg)

## Show Answer

**
Inverse degrees Celsius or inverse Kelvin (1/{}^oC \ or \ 1/K)
**

83 What is the approximate value of the coefficient of linear thermal expansion for copper?

(a) 0.1 \times 10^{-6}/{}^oC

(b) 17 \times 10^{-6}/{}^oC

(c) 10 \times 10^{-6}/{}^oC

(d) 100 \times 10^{-6}/{}^oC

## Show Answer

**
17 \times 10^{-6}/{}^oC
**

84 What happens to the length of a material when it’s heated?

(a) It remains the same

(b) It decreases

(c) It increases

(d) It depends on the material

## Show Answer

**
It increases
**

85 When a material undergoes linear thermal expansion, what happens to its length as the temperature rises?

(a) It decreases

(b) It remains constant

(c) It increases

(d) It oscillates

## Show Answer

**
It increases
**

86 How does the change in temperature relate to the change in length in linear thermal expansion?

(a) They are unrelated

(b) Change in length is directly proportional to change in temperature

(c) Change in temperature is inversely proportional to change in length

(d) None of these

## Show Answer

**
Change in length is directly proportional to change in temperature
**

#### Superficial Thermal Expansion

87 What is the term used to describe the increase in area of a substance due to heating?(a) Volumetric expansion

(b) Linear expansion

(c) Superficial expansion

(d) Anomalous expansion

## Show Answer

**
Superficial expansion
**

#### Volume (Cubical) Thermal Expansion of Solids

88 What is the increase in volume of a substance due to a rise in temperature called?(a) Superficial expansion

(b) Linear thermal expansion

(c) Volume thermal expansion

(d) Volumetric contraction

## Show Answer

**
Volume thermal expansion
**

89 Volumetric expansion is also known as:

(a) Cubical expansion

(b) Superficial expansion

(c) Linear expansion

(d) Radial expansion

## Show Answer

**
Cubical expansion
**

90 What does the coefficient of volume thermal expansion (\gamma) measure?

(a) The change in length per unit length

(b) The change in area per unit area

(c) The change in volume per unit volume

(d) The change in density per unit density

## Show Answer

**
The change in volume per unit volume
**

91 How is the increase in volume (\Delta V) related to the original volume (V) and the change in temperature (\Delta T) ?

(a) \Delta V \propto V \Delta T

(b) \Delta V \propto V

(c) \Delta V \propto \frac{\Delta T}{V}

(d) \Delta V \propto \frac{V}{\Delta T}

## Show Answer

**
\Delta V \propto V \Delta T
**

92 What is the proportionality constant for volume thermal expansion called?

(a) \alpha

(b) \beta

(c) \gamma

(d) \delta

## Show Answer

**
\gamma
**

93 In which direction do solids typically expand due to volume thermal expansion?

(a) They expand in all directions equally

(b) They expand only in the vertical direction

(c) They expand only in the horizontal direction

(d) They don’t expand in volume

## Show Answer

**
They expand in all directions equally
**

94 What is the relationship between the coefficient of linear thermal expansion (\alpha) and volumetric expansion (\gamma) for solids?

(a) \alpha = \gamma

(b) \gamma = 3 \alpha

(c) \alpha = 3 \gamma

(d) \alpha = 2 \gamma

## Show Answer

**
\gamma = 3 \alpha
**

95 What is the approximate value of the coefficient of volumetric expansion for copper?

(a) 0.1 \times 10^{-6}/ {}^0C

(b) 51 \times 10^{-6}/ {}^0C

(c) 10 \times 10^{-6}/ {}^0C

(d) 100 \times 10^{-6}/ {}^0C

## Show Answer

**
51 \times 10^{-6}/ {}^0C
**

### Thermal Expansion of Liquids

96 Which type of expansion can occur in liquids when they are heated?(a) Linear expansion

(b) Superficial expansion

(c) Volumetric expansion

(d) All of these

## Show Answer

**
Volumetric expansion
**

97 What is the increase in volume of a liquid due to heating called?

(a) Linear expansion

(b) Superficial expansion

(c) Volumetric expansion

(d) Apparent expansion

## Show Answer

**
Volumetric expansion
**

#### Real Expansion of Liquids

98 Which type of thermal expansion in liquids is independent of the expansion of the container?(a) Linear expansion

(b) Superficial expansion

(c) Real expansion

(d) Apparent expansion

## Show Answer

**
Real expansion
**

99 What is the term used to describe the real increase in volume of a liquid per unit original volume per unit degree rise in temperature?

(a) Superficial expansion

(b) Linear expansion

(c) Coefficient of apparent expansion

(d) Coefficient of real expansion

## Show Answer

**
Coefficient of real expansion
**

#### Apparent Expansion of Liquids

100 What is the term used to describe the apparent increase in volume of a liquid per unit original volume per unit degree rise in temperature?(a) Superficial expansion

(b) Linear expansion

(c) Coefficient of apparent expansion

(d) Coefficient of real expansion

## Show Answer

**
Coefficient of apparent expansion
**

#### Anomalous Expansion of Water

101 What is the term for the unusual expansion behavior of water between 0 \ {}^oC \ and \ 4 \ {}^oC ?(a) Superficial expansion

(b) Anomalous expansion

(c) Real expansion

(d) Apparent expansion

## Show Answer

**
Anomalous expansion
**

102 What is the temperature range within which water exhibits its anomalous behavior?

(a) 0 \ {}^oC \ to \ 100 \ {}^oC

(b) 0 \ {}^oC \ to \ 4 \ {}^oC

(c) 4 \ {}^oC \ to \ 100 \ {}^oC

(d) Below 0 \ {}^oC

## Show Answer

**
0 \ {}^oC \ to \ 4 \ {}^oC
**

103 At which temperature does water have its maximum density?

(a) 0 \ {}^oC

(b) 4 \ {}^oC

(c) 100 \ {}^oC

(d) None \ of \ these

## Show Answer

**
4 \ {}^oC
**

### Applications and Consequences of Thermal Expansion

#### Railway lines

104 Why do railway engineers leave a small gap between two railway tracks when laying them?(a) To save materials

(b) To make maintenance easier

(c) To prevent accidents caused by thermal expansion

(d) To reduce noise pollution

## Show Answer

**
To prevent accidents caused by thermal expansion
**

#### Opening of Tight Jar Lid

105 How can you loosen a tight lid on a glass jar using thermal expansion?(a) By freezing the lid

(b) By holding the lid under hot water

(c) By tapping the lid with a hammer

(d) By using a wrench

## Show Answer

**
By holding the lid under hot water
**

#### Transmission Lines

106 Why do transmission lines sag more in the summer compared to winter?(a) Due to the weight of the lines

(b) Due to thermal expansion of the lines

(c) Due to increased electricity demand

(d) Due to wind pressure

## Show Answer

**
Due to thermal expansion of the lines
**

#### Bimetallic Strip

107 What is the principle behind the operation of a bimetallic strip?(a) Equal expansion of two metals

(b) Differential expansion of two metals

(c) Magnetic attraction

(d) Optical refraction

## Show Answer

**
Differential expansion of two metals
**

### Heat Capacity and Specific Heat Capacity

#### Heat Capacity (Thermal Capacity)

108 What is the term used to describe the quantity of heat required to raise the temperature of a substance by 1 \ {}^oC \ or \ 1 K ?(a) Heat capacity

(b) Specific heat capacity

(c) Temperature coefficient

(d) Thermal conductivity

## Show Answer

**
Heat capacity
**

109 What is the mathematical expression for heat capacity (C_m) in terms of change in heat (\Delta Q) and change in temperature (\Delta T) ?

(a) C_m = \frac{\Delta Q}{\Delta T}

(b) C_m = \frac{\Delta T}{\Delta Q}

(c) C_m = \Delta Q × \Delta T

(d) C_m = \Delta Q - \Delta T

## Show Answer

**
C_m = \frac{\Delta Q}{\Delta T}
**

110 Which unit is used to express heat capacity in the Standard International System?

(a) Joule per kilogram (J/kg)

(b) Joule per Kelvin (J/K)

(c) Celsius per joule ({}^oC/J)

(d) Kilogram per Kelvin (kg/K)

## Show Answer

**
Joule per Kelvin (J/K)
**

111 What symbol is commonly used to represent heat capacity?

(a) Q

(b) H

(c) C_m

(d) T

## Show Answer

**
C_m
**

112 Heat capacity is also known as:

(a) Thermal volume

(b) Temperature resistance

(c) Thermal inertia

(d) Thermal capacity

## Show Answer

**
Thermal capacity
**

#### Specific Heat Capacity (Specific Heat)

113 What is the term used to describe the quantity of heat needed to raise the temperature of 1 kilogram of a substance by 1 \ {}^oC \ or \ 1 K ?(a) Heat capacity

(b) Specific heat capacity

(c) Heat resistance

(d) Thermal conductivity

## Show Answer

**
Specific heat capacity
**

114 What is the symbol used to represent specific heat capacity?

(a) Q

(b) c

(c) S

(d) H

## Show Answer

**
c
**

115 Specific heat capacity is also known as:

(a) Temperature coefficient

(b) Thermal conductivity

(c) Heat capacity

(d) Specific heat

## Show Answer

**
Specific heat
**

116 What is the mathematical expression for specific heat capacity (c) ?

(a) c = \frac{\Delta Q}{m \Delta T}

(b) c = m \Delta T

(c) c = \frac{Q}{m}

(d) c = \frac{T}{\Delta Q}

## Show Answer

**
c = \frac{\Delta Q}{m \Delta T}
**

117 What is the unit of specific heat capacity in the International System of Units (SI)?

(a) Joules per Kelvin (J/K)

(b) Joules per kilogram per Kelvin (J/(kg.K))

(c) Kelvin per Joule (K/J)

(d) Watts per meter per Kelvin (W/(m.K))

## Show Answer

**
Joules per kilogram per Kelvin (J/(kg.K))
**

118 What is the specific heat capacity of water?

(a) 100 \ J/kg.K

(b) 500 \ J/kg.K

(c) 1000 \ J/kg.K

(d) 4190 \ J/kg.K

## Show Answer

**
4190 J/kg.K
**

### Latent Heat and Phase Change

119 What is a phase change in a substance?(a) A change in temperature

(b) A change in color

(c) A change in physical characteristics from one form to another

(d) A change in chemical composition

## Show Answer

**
A change in physical characteristics from one form to another
**

120 When ice melts at 0 \ {}^oC , what is the temperature of the resulting water?

(a) 0 \ {}^oC

(b) 100 \ {}^oC

(c) Above 0 \ {}^oC

(d) Below 0 \ {}^oC

## Show Answer

**
0 \ {}^oC
**

121 What is the term used to describe the heat required to change the physical state of a substance without changing its temperature?

(a) Thermal capacity

(b) Thermal conductivity

(c) Latent heat

(d) Specific heat

## Show Answer

**
Latent heat
**

122 Latent heat is also known as:

(a) Hidden Heat

(b) Thermal Energy

(c) Sensible Heat

(d) Specific Heat

## Show Answer

**
Hidden Heat
**

### Latent Heat of Fusion

123 The heat energy required to melt a substance without change in temperature is called:(a) Specific heat capacity

(b) Latent heat of fusion

(c) Thermal conductivity

(d) Heat capacity

## Show Answer

**
Latent heat of fusion
**

124 What happens when liquids solidify (freeze) in terms of heat release?

(a) They release no heat

(b) They release heat equivalent to the latent heat of fusion

(c) They release heat equivalent to the specific heat

(d) They release heat equivalent to their boiling point

## Show Answer

**
They release heat equivalent to the latent heat of fusion
**

### Specific Latent Heat of Fusion

125 The heat energy required to change unit mass from solid to liquid without a change in temperature is called:(a) Thermal conductivity

(b) Heat capacity

(c) Specific latent heat of fusion

(d) Latent heat of fusion

## Show Answer

**
Specific latent heat of fusion
**

126 What is the formula to calculate the heat energy required for a phase change using specific latent heat of fusion (L_f) ?

(a) \Delta Q = mL_f

(b) \Delta Q = \frac{m}{\Delta T}

(c) \Delta Q = m \Delta T

(d) \Delta Q = L_f \Delta T

## Show Answer

**
\Delta Q = mL_f
**

127 What is the symbol used to represent specific latent heat of fusion?

(a) L_f

(b) Q

(c) H

(d) S

## Show Answer

**
L_f
**

128 What is the SI unit of specific latent heat of fusion?

(a) Joule per Kelvin (J/K)

(b) Joule per meter (J/m)

(c) Joule per kilogram (J/kg)

(d) Joule per second (J/s)

## Show Answer

**
Joule per kilogram (J/kg)
**

### Latent Heat of Vaporization

129 The heat energy required to transfer a substance from liquid state to gaseous state without a change in temperature is called:(a) Specific heat capacity

(b) Latent heat of vaporization

(c) Thermal conductivity

(d) Heat capacity

## Show Answer

**
Latent heat of vaporization
**

### Specific Latent Heat of Vaporization

130 The heat energy required to change unit mass from liquid to gas without a change in temperature is called:(a) Thermal conductivity

(b) Heat capacity

(c) Specific latent heat of vaporization

(d) Latent heat of fusion

## Show Answer

**
Specific latent heat of vaporization
**

131 What is the formula to calculate the heat energy required for a phase change using specific latent heat of vaporization (L_v) ?

(a) \Delta Q = mL_v

(b) \Delta Q = \frac{m}{\Delta T}

(c) \Delta Q = m \Delta T

(d) \Delta Q = L_f \Delta T

## Show Answer

**
\Delta Q = mL_v
**

132 What is the symbol used to represent specific latent heat of vaporization?

(a) L_v

(b) Q

(c) H

(d) S

## Show Answer

**
L_v
**

133 What is the SI unit of specific latent heat of vaporization?

(a) Joule per Kelvin (J/K)

(b) Joule per meter (J/m)

(c) Joule per kilogram (J/kg)

(d) Joule per second (J/s)

## Show Answer

**
Joule per kilogram (J/kg)
**

134 Which phase change involves the direct transition from a solid to a gas without passing through the liquid state?

(a) Freezing

(b) Melting

(c) Sublimation

(d) Condensation

## Show Answer

**
Sublimation
**

135 The latent heat of fusion for a given substance is ___________ the latent heat of vaporization for the same substance.

(a) Greater than

(b) Less than

(c) Equal to

(d) Unrelated to

## Show Answer

**
Greater than
**

136 What is the process called when a solid changes into a liquid?

(a) Sublimation

(b) Condensation

(c) Freezing

(d) Melting

## Show Answer

**
Melting
**

### Evaporation of Liquids

137 When a liquid changes into a gas, it is known as:(a) Melting

(b) Freezing

(c) Evaporation

(d) Condensation

## Show Answer

**
Evaporation
**

138 The process in which a gas changes into a liquid is called:

(a) Sublimation

(b) Condensation

(c) Freezing

(d) Melting

## Show Answer

**
Condensation
**

139 What is the term for the change of state from a liquid to a solid?

(a) Boiling

(b) Condensation

(c) Freezing

(d) Sublimation

## Show Answer

**
Freezing
**

140 Which factor affects the rate of evaporation by providing kinetic energy to liquid molecules?

(a) Nature of liquid

(b) Temperature of surrounding

(c) Temperature of the liquid

(d) Area of the exposed surface

## Show Answer

**
Temperature of the liquid
**

141 In which season do wet clothes dry more slowly due to the presence of high water vapor in the air?

(a) Autumn

(b) Summer

(c) Rainy season

(d) Spring

## Show Answer

**
Rainy season
**

142 Why do wet roads dry out quickly?

(a) Due to the low temperature

(b) Due to low air pressure

(c) Due to increased surface area

(d) Due to the absence of wind

## Show Answer

**
Due to increased surface area
**

143 What factor affects the rate of evaporation by reducing the presence of water vapor in the air?

(a) Dryness of the air

(b) Nature of liquid

(c) Movement of air

(d) Temperature of the surrounding

## Show Answer

**
Dryness of the air
**

144 On a windy day, what happens to the rate of evaporation?

(a) It decreases

(b) It remains the same

(c) It increases

(d) It depends on other factors

## Show Answer

**
It increases
**

145 Which factor primarily depends on the liquid’s boiling point?

(a) Temperature of the liquid

(b) Nature of liquid

(c) Movement of air

(d) Area of the exposed surface

## Show Answer

**
Nature of liquid
**

146 What role does the temperature of the surrounding play in evaporation?

(a) It has no effect on evaporation

(b) It increases the air pressure

(c) It provides kinetic energy to liquid molecules

(d) It decreases the rate of evaporation

## Show Answer

**
It provides kinetic energy to liquid molecules
**

147 How does the presence of water vapor in the air affect evaporation?

(a) It increases the rate of evaporation

(b) It has no effect on evaporation

(c) It decreases the rate of evaporation

(d) It depends on the temperature

## Show Answer

**
It decreases the rate of evaporation
**

### Evaporation causes Cooling

148 What causes the cooling effect when a liquid evaporates?(a) Increased kinetic energy of molecules

(b) Heat absorbed by the liquid

(c) Molecules taking heat energy with them

(d) Increased temperature of the liquid

## Show Answer

**
Molecules taking heat energy with them
**

149 Which substance evaporates more quickly, water or spirit?

(a) Water

(b) Spirit

(c) They evaporate at the same rate

(d) Depends on temperature

## Show Answer

**
Spirit
**

150 Why does your palm feel cold when spirit is spilled on it and quickly evaporates?

(a) The spirit is cold by nature

(b) Your palm generates cold when in contact with spirit

(c) Evaporation of spirit causes cooling

(d) The spirit takes in heat from your palm

## Show Answer

**
Evaporation of spirit causes cooling
**

151 How does the cooling effect of evaporation help maintain a stable body temperature in humans?

(a) By increasing body temperature

(b) By preventing perspiration

(c) By lowering body temperature through sweat evaporation

(d) By slowing down metabolic processes

## Show Answer

**
By lowering body temperature through sweat evaporation
**

152 According to the kinetic theory, what happens to the temperature of a liquid when more energetic molecules escape through evaporation?

(a) The temperature increases

(b) The temperature remains the same

(c) The temperature decreases

(d) It depends on the liquid

## Show Answer

**
The temperature decreases
**

153 Which statement is true regarding the cooling effect of evaporation?

(a) Evaporation warms the surface left behind

(b) Evaporation cools the surface left behind

(c) Evaporation is unrelated to temperature changes

(d) Evaporation only occurs at high temperatures

## Show Answer

**
Evaporation cools the surface left behind
**

154 Why does perspiration help cool the human body?

(a) It releases heat into the body

(b) It contains cold substances

(c) It prevents body temperature from changing

(d) It cools the body through evaporation

## Show Answer

**
It cools the body through evaporation
**

### Applications of Cooling by Evaporation

#### Cooling by Fans

155 Why do fans provide a cooling sensation in hot weather?(a) Fans lower the room temperature

(b) Fans increase the rate of boiling

(c) Fans accelerate the rate of evaporation, which cools the body

(d) Fans increase humidity levels

## Show Answer

**
Fans accelerate the rate of evaporation, which cools the body
**

#### Fever Control

156 How does placing a wet towel on the forehead help control fever?(a) It lowers room temperature

(b) It absorbs heat from the environment

(c) It increases body temperature

(d) It utilizes the cooling effect of evaporation to lower the head’s temperature

## Show Answer

**
It utilizes the cooling effect of evaporation to lower the head’s temperature
**

#### Refrigerator

157 Which part of a refrigerator is responsible for the cooling effect through evaporation?(a) Evaporator

(b) Refrigerant

(c) Expansion valve

(d) None of these

## Show Answer

**
Evaporator
**

158 What environmental concern is associated with the use of chlorofluorocarbon (CFC) chemicals as refrigerants in old refrigerators?

(a) CFCs contribute to global warming

(b) CFCs release harmful odors

(c) CFCs can damage the ozone layer

(d) CFCs are explosive

## Show Answer

**
CFCs can damage the ozone layer
**

159 What is the purpose of the compressor in a refrigerator?

(a) To evaporate the refrigerant

(b) To condense the refrigerant

(c) To maintain room temperature

(d) To compress the refrigerant, raising its temperature

## Show Answer

**
To compress the refrigerant, raising its temperature
**

160 What kind of refrigerant is being used in modern refrigerators to address environmental concerns?

(a) Hydro fluorocarbon (HFC)

(b) Chlorofluorocarbon (CFC)

(c) Carbon dioxide (CO_2)

(d) Methane (CH_4)

## Show Answer

**
Hydro fluorocarbon (HFC)
**

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